microsoft/qlib · error · ValueError

Cannot find user {}

Error message

Cannot find user {}

What it means

Raised by UserManager.save_user_data when the given user_id is not a key in the in-memory self.users dict. Saving serializes the user's account, strategy and model pickles, so it requires the user to have been loaded/created in this UserManager instance first.

Source

Thrown at qlib/contrib/online/manager.py:84

        cur_user_list = list(self.users)
        if user_id in cur_user_list:
            raise ValueError("User {} has been loaded".format(user_id))
        else:
            trade_account = Account(0)
            trade_account.load_account(account_path)
            strategy = load_instance(strategy_file)
            model = load_instance(model_file)
            user = User(account=trade_account, strategy=strategy, model=model)
            return user

    def save_user_data(self, user_id):
        """
        save a instance of User() to user data path
            Parameter
                user_id : string
        """
        if not user_id in self.users:
            raise ValueError("Cannot find user {}".format(user_id))
        self.users[user_id].account.save_account(self.data_path / user_id)
        save_instance(
            self.users[user_id].strategy,
            self.data_path / user_id / "strategy_{}.pickle".format(user_id),
        )
        save_instance(
            self.users[user_id].model,
            self.data_path / user_id / "model_{}.pickle".format(user_id),
        )

    def add_user(self, user_id, config_file, add_date):
        """
        add the new user {user_id} into user data
        will create a new folder named "{user_id}" in user data path
            Parameter
                user_id : string
                init_cash : int
                config_file : str/pathlib.Path()

View on GitHub (pinned to 79633dd950)

Solutions

  1. Call um.load_users() after constructing UserManager so existing users are in um.users.
  2. Verify the id: assert user_id in um.users before save_user_data(user_id).
  3. If the user is new, create it first with create_user/add_user before saving.

Example fix

# before
um = UserManager(user_data_path=p)
um.save_user_data("u1")  # ValueError: Cannot find user u1

# after
um = UserManager(user_data_path=p)
um.load_users()               # populate um.users from disk
if "u1" in um.users:
    um.save_user_data("u1")
Defensive patterns

Strategy: validation

Validate before calling

um.load_users()
assert user_id in um.users, f"user {user_id} not loaded; check users_file and folders"
um.save_user_data(user_id)

Type guard

def can_save_user(um, user_id) -> bool:
    return user_id in um.users

Prevention

When it happens

Trigger: Calling save_user_data(user_id) before load_users() or before create_user added that id; passing a typo'd or removed user_id; calling save on a fresh UserManager constructed with a data_path but never populated.

Common situations: Scripts that assume users are auto-discovered from disk without calling load_users(); user was removed earlier in the session and then saved; case/format mismatch of the id string (e.g. '01' vs '1').

Related errors

AI-assisted analysis of microsoft/qlib@79633dd950 (2026-08-15). Data as JSON: /api/errors/ea13532b8d0cb605. Report an issue: GitHub.